


String Theory

by noero



Category: Voltron: Legendary Defender
Genre: Accidental Soul Bond, Alternate Universe - Canon Divergence, First Time, Frottage, Future Fic, Leader!Keith lights my fire, M/M, Plot What Plot/Porn Without Plot
Language: English
Status: Completed
Published: 2016-12-27
Updated: 2016-12-27
Packaged: 2018-09-12 10:04:02
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 4,340
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/9067054
Author URL: https://archiveofourown.org/users/noero/pseuds/noero
Summary: The prospect of piloting the Red Lion had excited Lance at first, even if the mere thought of abandoning the Blue Lion made him uneasy. In hindsight, that should have been his first clue that something was bound to go wrong. Omnipresent robot lions were usually right about these things.





	

**Author's Note:**

> So this explicitly features Black Paladin Keith as well as Red Paladin Lance because I’m an awful person and I probably hate everything. It’d be cool tho if we just pretend Shiro is fine and on vacay, chillin on a beach somewhere because I want everyone to be happy and I’m terrified of season 2. 
> 
> This was written as part of the klance secret santa exchange for [tabi-does-art](http://tabi-does-art.tumblr.com) who requested a Soulmate AU. I unfortunately came down with the flu a week before the posting deadline and was unable to finish everything I had planned. This admittedly should have been at least twice as long and my original outline called for two chapters, and possibly a third. Many of the transitions are very incomplete and all editing was done under the influence of a mid-grade fever. I apologize for all inconsistencies, typos, and weird sentences. I may write some companion pieces to better explain what's going on in this 'verse or I may just come back and do a very heavy edit of this piece when I'm more coherent. In the meantime, however, I know this is a hot mess. 
> 
> The title is taken from the Les Friction song of the same name because it gives me feelings.

“The effects...” Allura gives a wary glance to Coran, taking in a steady breath before she finishes. “Can transcend lifetimes.” 

The finality of her words make Lance’s stomach bottom out. He squeaks, half indignant and half disbelieving, “Are you kidding me? You’re saying we’re… _soulmates_ or something? No. No can do. I refuse.”

Keith shuffles awkwardly beside him, clearly uncomfortable, but manages to hold it together. “I did what I had to do. She wasn’t going to accept you and we were running out of time. Someone had to do _something_." Keith's voice begins to wear desperate toward the end. "Now grow up and act like you're part of this team.”

As soon as he's done, the room goes quiet and the air lays heavy on them. _Act like you're part of this team_ , Lance thinks, a hollow and soft way to say he's never been so. The first major push comes from him, hitting Keith hard enough he flinches before the vitriol even leaves Lance's tongue. However unintentional, Keith recognizes that slimy emotion Lance bleeds so well. The fight they have that night is a big one.

* * *

For some reason the tired words Lance says to himself a hundred times a day sting far worse when they come out of Keith's mouth. He has fixated enough on this phenomena to recognize the problems between them go deeper than he's willing to address out loud. Ignoring the problem has always been an easier option, never mind this has never once proven an effective way to solve his problems. It's _easier_ and Lance likes easy. So if he closes his eyes and ignores his ears, he forgets where he is. The soft computer hum becomes the warm, nighttime breeze filtering through his bedroom window. The unnatural glow of the track lighting is pale moonlight through the curtains. The stillness is a calm summer night. 

For five minutes, he's not on an alien castle that travels through space. For five minutes, he's not leveling the weight of the universe on his shoulders. For five minutes, his life is simple. Life is _easy_.

For five minutes, Lance is happy.

But Lance isn’t a child anymore and he remembers how he’s too old to play pretend when the illusion is interrupted. He rolls over to stare at the ceiling and the long-familiar ache in his chest melds to the fuzziness of his mind. It’s not like the mind meld exercise, which is less of a relief than it sounds. Lance is not inundated with visual cues that mean nothing to him, outside their context in someone else's mind, and he mourns the simplicity of only seeing someone he can't decide if he loves or hates through the peripherals of intimacy. This is more like how their lions communicate with them. A push of raw emotion. An abstract desire. Hunger. Fear.

It’s loneliness, and so distinctly _Keith_ that it makes Lance curl in on himself.

Being privy to someone's personal feelings, with neither party having a say in the matter, is an achingly voyeuristic act. There is no silver lining. This sort of bond isn't good for the team. When the day ends and the adrenaline fades, it leaves them feeling almost dirty. The signals were difficult to discern at first but as the weeks dragged into months, Lance could now decipher each push for what it was. Lance knows when Keith is angry, happy, sad, or aroused. He knows when Keith misses Shiro so much it overwhelms him. And Lance is a lot of awful things, even he will admit that much, but stupid is not one of them. Playing dumb is just _easy_. 

The spiteful, jealous part of Lance still blames Keith for everything. He blames Keith, even knowing how much pain Keith is in. He blames Keith, even knowing it wasn't Keith at all. Lance blames Keith knowing it was his own fault, all Lance, screwing everything up six ways to Sunday.

The prospect of piloting the Red Lion had excited Lance at first, even if the mere thought of abandoning the Blue Lion made him uneasy. In hindsight, that should have been his first clue that something was bound to go wrong. Omnipresent and sentient robot lions were usually right about these things. However, when Keith was the one to ask Lance to step in for him, when he didn't ask anyone else, that splitting need Lance had to prove himself took hold and the idea of backing down, even for well-founded reasons, didn't occur to him for even a second. So yes, of course he'd pilot the Red Lion - the fastest and most agile and in need of the best pilot - and he'd do it a hundred times better than Keith ever did. 

With the decision made, Keith wanted to move quickly since every day they spent twiddling their thumbs, as he put it, God knew what was happening to Shiro. Keith made a valid point, however illogical the plan was. Even Allura advised they take things slower, as the bonds between lion and paladin were complex and delicate. What they were doing was dangerous. Keith unfortunately wasn't having it, and Lance, thinking he understood that sentiment for once, backed Keith up to the fullest. After having spent the previous month ignoring any and all of Keith's half-baked commands - unless Allura repeated them in her far more pleasant voice - their morale had sunk to an all-time low. So upon seeing Lance stand up for Keith, and with such meaningful conviction, Allura conceded to the shaky plan, albeit with reservations. 

Things, however, went sour quickly after that. 

Allura formed a bond with the Blue Lion like it was no big deal. It had stung Lance hard, despite his knowing the princess had an inherent bond with all the lions being Altean and all. They'd watched her take over as a confident pilot, like she'd done it her whole life. And for the first time that he could remember, Allura wasn't one of Lance's favorite people.

"That's promising," Keith had observed, hand steadying himself where it lay on the headrest behind Lance. He leaned in, voice far steadier than Lance felt. "You ready?"

There was a wariness about Keith in that moment that Lance didn't appreciate, like Keith knew deep down that the Red Lion would never accept him. Keith could take Lance's confidence like that, knock it out of him like knocking the wind form his lungs, and it happened just then in the very wrong moment. Lance is, after all, a weak and pathetic person. 

Of course she rejected him, and for an awful second Lance couldn't decide if he wanted to cry or scream. This had been his last opportunity to prove himself and he'd blown it. 

Keith, however, was determined. He coaxed her and was so stubborn and relentless in doing so that he forced the bond by blending it with his own. Lance never did quite understand how quintessence worked and just blindly accepted that it was somewhere between science and magic. How Keith even managed this feat seemed impossible, but reasoned it perhaps an alien thing. All Lance really knew in that moment was that he felt a wave of _something_ toward Keith and it scared him more than anything they'd encountered in the whole six months they'd previously been in space.

The two of them knew something was very wrong the minute they stepped out of the hanger and it felt like an invisible string ran between them. It was taut that first night, bothering them both, and they'd sought out some form of guidance from Allura but she'd been unable to offer them any solution. Even Altean magic, it seemed, could not undo what they'd unwittingly done. 

Lance now does everything he can to pretend it's no big deal, a casualty of this weird war they fight, all while knowing it is a very big deal. He is intimately aware of Keith’s bleariness, the fear that colors the edge of anger, and the indecision that plagues his sense of authority. It crashes on him every time Keith screws up and Lance is unable stop it. The biggest tragedy is that the prod of emotion from Keith is gentle enough that Lance never sees it coming until it's too late. This is a useless ability that does nothing but make Lance feel like a tourist watching Keith through the glass, without any of the responsibility that should come with seeing so deep into someone. So he buries Keith’s feelings within his own, crates them, and sends them barreling down light years to the bottom of Earth’s oceans. 

Life is painfully unfair.

Tonight is no exception. When the next wave of emotion hits him, a strange mix of uncertainty and isolation, Lance curses and yanks his blanket over his head. Keith is upset about something, he realizes, and it forms an uncomfortable swell in the pit of Lance's own stomach. He hates this. Hates this more than words can express. 

After a few more fits of twisting and turning in his bed, Lance throws his covers off and stomps out of his room. He's already standing in front of Keith's door before he even knows what he wants to say or do. The longer he stands in silence, the worse he feels, so with a soft sigh he gently rattles his knuckles against the door and frowns to himself. This shouldn't be so hard. 

The door slides open a few ticks later and Keith is shirtless, freshly showered, and pleasantly annoyed. But not asleep. “What is it now, Lance? It's late.”

He looks smaller without his jacket, lean and lithe muscle on a strong but compact frame. Lance grins and leans heavily into his doorframe, conjuring up a reasonable excuse to be standing in Keith's doorway. He flashes a bandaged hand. “Heard you still had some of the good stuff we gathered from Xoeliv.”

Keith rolls his eyes and waves Lance inside, the door sliding shut behind him. “The next time someone tells you to be efficient with your use of rare alien painkillers, listen to them.” Keith shuffles through papers and Altean books and Lance how he can ever find anything in the general state of chaos that has become Keith’s bedroom. “What’d you do anyway? Pretty sure you spent the whole day goofing off downstairs while Hunk helped Pidge install the upgrades.”

“I was helping,” Lance supplies and Keith shoots him a deadpan look over his shoulder. “It’s called _teamwork_ my friend, though I know that’s a difficult concept for you to comprehend.”

Keith turns to full-on glare at him, vial of miracle salve in hand, and Lance folds his arms over his chest. It so happened that Lance’s share was used for a - very valid - sprained ankle. It wasn’t his fault Coran wouldn’t deem the injury severe enough for the cryopod. He believes Keith just prefers for him to suffer.

As Keith walks over, still looking every bit the high-strung prick he very much is, his eyes drift down Lance’s body. For all things holy and good, Lance knows Keith doesn’t even know he’s doing it. The true tragedy of their time. 

Keith catches Lance’s eye and raises an eyebrow.

“Fine. I was showing off some of my very dance sweet moves and consequently slammed my hand into a metal post. An unfortunate casualty of my being continually awesome. Are you happy now?”

Laughter swells from Keith and the sound is filled with a soft buoyancy that Lance is pleased to have put there, however unintentional the series of events that led him there had been. “Yeah, I’m pretty happy.”

Lance reaches for the vial but Keith pulls back, shaking it. “I don’t think so. I’m not giving it to you so you can waste it every time you get a paper cut. Hold out your hand.”

Lance complies, if not with a grudge. “If you wanted to hold my hand, all you had to do-”

“ _Lance_.”

He blanches beneath Keith’s tone, the way he’s managed to emulate Shiro’s inflection is more irritating and uncomfortable to Lance than anything he actually says. He complies without further argument, wincing as Keith tears off the bandage.

When Keith’s thumb slides over his palm, Lance looks up from Keith’s bony wrists to watch as a lock of hair falls in Keith’s face. Keith is beautiful in a way that Lance has long since recognized - the way he moves, the way he smiles, the way he seems so unflappable - but it’s more visceral now, something that catches Lance’s eye in the strangest moments. The fingers twitch at his side.

Lance recalls sobering moments in the flight class they shared back at the Garrison, watching Keith - really _watching_ him - ace through simulations with such a lack of effort that made Lance feel like he was two inches tall. He’d spend hours at night venting to Hunk about how he would be better, _greater_ than Keith one day - just watch him - but then Lance would fall asleep thinking of cutting class with Keith to share secrets and stories. Lance always made friends easily, but he'd never wanted to be friends with someone so badly as with the one person who never gave him the time of day. Even now, with their lives quite literally intertwined, there may as well have been light years between them. 

“What are you thinking about?”

A flush spreads across Lance’s features and Keith tilts his head, expression curious. Lance gives a nervous chuckle in an effort to ease the tension, but the sound comes out thin and worn. He lays his head down on Keith’s shoulder to hide the red tinge on his cheeks even if he’s never fooled anyone.

They have an easy intimacy when they’re alone but neither of them know what to do with it. That much hasn’t changed.

“What are you doing?” There’s an edge to Keith’s voice.

Lance tucks his face further into the crook of Keith’s neck. He smells nice. “I’m tired.”

Keith sighs, exasperated. The air crackles lightly and Lance feels the push of frustration. “Are we ever going to talk about this?”

Lance sucks in a breath and opens one eye to glance over Keith’s shoulder toward the spot above his bed where he marks off the days. The longest scratch marks the day they landed in the first wormhole and the deepest, thrust in a good inch, marks the day they reunited after the second. Lance idly wonders if the princess has any idea the infallible Keith is carving up her pristine castle walls. It’s hundreds and hundreds of shallow lines panning from the corner above his pillow and down the length of his bed. Totaled up, the days add up to just over three years, or so Keith says, and it makes Lance's stomach turn.

Keith’s ugly calendar reminds him that even if they make it back, he can never go home.

“What’s there to talk about?” Lance replies curtly. “I haven’t had a full night’s sleep in months because you won’t stay out of my head. Annoying.”

Keith is quiet for a minute, pulse thrumming against Lance’s cheek. “I don’t mean to,” he finally says. “You keep calling to me.”

Lance’s heart jumps into his throat. Of all the things wrong, he’s painfully aware he’s not alone. He wonders at how it feels for Keith to feel his own pushes, given how Lance buries himself in bitterness at least have the time. He wants to ask, wants to know. “Try harder,” he says, instead.

“You don’t...” Keith’s tone is pinched, and Lance can practically hear the grind of his teeth. Each tender moment they share is a high wire dance between isolation and intimacy. Gravity was bound to make them fall one way or the other. “Just tell me what you want.”

_You_. Lance keeps his mouth shut, eyes flashing again over the smooth plane of Keith’s shoulder. Keith’s need to _fix_ every little thing drives Lance crazy with the way Keith hovers over him for all the wrong reasons. He is terrible. Awful. A mess.

“You need me,” Lance says. “I want you to say it.”

Keith pushes Lance back to look him in the eye. Without further warning or preamble he slides a palm behind Lance’s neck and pulls him forward just enough for their lips to meet.

Keith doesn't kiss like anyone Lance has kissed before. He's firm, self-assured, and a little greedy. There is nothing tentative there. Nothing soft or delicate like the touch of a girl. Lance grasps at the fast-fading memories of his seventh-grade girlfriend with her cotton-candy pink braces, of the tall brunette in their dorm hall at the Garrison with her green paisley bed sheets, or any of the other girls that fell in-between, with their soft lips and soft curves.

Keith is none of that. Just certain and unapologetic, all hard edges, impatient and bold, like he’s planned this for years.

Lance opens his mouth - to object, he thinks - but instead invites Keith to explore deeper, allowing his teeth to tug faintly at his bottom lip and tongue to press inside his mouth.

The kiss is good - experienced - and a quiet jealousy flares in Lance’s belly thinking of all the game nights with Hunk and Pidge that Keith never showed up for. He thinks of the rare nights Keith wasn’t pushing himself to exhaustion on the training deck but instead of the nights he spent in the control room chatting with Allura.

Somewhere in-between the carvings on Keith’s wall, the lines that connect them are almost fluid. They grow and stretch and change, cracks in the ice that threaten to break when Lance tries to cross. Lance isn’t sure where he falls on Keith’s list and he hates that ugly stab of envy that mingles with and sours all the things he loves about Keith.

In the same instant, Keith tenses and the sliver of rage fades to guilt. In a panic, Lance digs his fingers into Keith’s bare waist and pulls him closer. He needs to h old on. For all the doubts, Lance needs to believe that Keith _wants_ him in every sense of the word, and it doesn’t matter why.

When they finally pull apart Keith levels him with a cocksure grin, a hand at Lance’s waist and fingers ghosting over his waist. There’s a glint in his eye, like he just won a game Lance didn’t even realize they were playing. "Yeah?"

“You can…” Lance’s throat is dry, voice cracking and shaking even though he keeps it in a low whisper. “You can do it again.”

Keith kisses his neck this time and Lance shivers, eyes fluttering shut. His mouth starts moving on instinct, “ _Right there. God. Are we really going to-_ ”

“I’m barely touching you,” Keith admonishes, sneaking his hands beneath the hem of Lance’s shirt. Lance trembles. “Calm down.”

Before he can come back with a scathing retort Keith continues his onslaught, dragging his mouth down Lance’s neck until he reaches the valley of his collarbone, tugging Lance’s shirt up until he gets the message and helps himself squirm out of the fabric.

“So,” Lance starts, awkward. Excited. “Wanna move this to your bed or are we just gonna chill here against the wall?”

Keith stops and glances over his shoulder to the mess of blankets and sheets twisted over his mattress. He looks back to Lance and quirks an eyebrow. “Sure you’re up for this?”

Lance scoffs. “I’ve been _up_ for this for at least the last two minutes.” He grinds his hips against Keith for added emphasis and his skin goes hot in embarrassment, despite being the one to draw attention to it. “Or are you just not familiar with the standard equipment?”

Keith frowns, glaring at Lance as he hooks a finger into a belt loop on Lance’s jeans before yanking him toward the bed. “That’s not what I meant.”

Lance gives him a playful smile as he falls on the mess of blankets, trying - and failing - to pull Keith down with him. “You’re not scared, are you?”

“Nah.” Keith shrugs, grinning back before slipping off his pants - modesty never his forte - to reveal skin-tight gray boxers that do nothing to hide the generous expanse of his body. Pride fills Lance in knowing that his presence did that to Keith, never mind his own erection is straining uncomfortably against his jeans.

When Keith joins him on the bed he half-tackles Lance, kissing him with abandon and searching across his body without hesitation. Their kisses are poorly timed and half the time they miss their target, Lance’s mouth landing on Keith nose or in his hair, teeth knocking together and a tongue sliding down his neck.

This is better than every single fleeting late-night fantasy Lance harbored of stripping Keith down on the training deck and shamelessly fucking him into oblivion, he decides. The moment Keith’s fingertips ghost beneath the waistband of his jeans and brush along the course hair beneath his navel, Lance makes a strangled noise.

"Hanging in there, cargo pilot?"

The insult causes a puzzling reaction, and one that Lance reasons he’ll question for the rest of his living days. Instead igniting self-justified outrage, his dick gives a rude jerk. The next words from Lance’s mouth are frighteningly lacking in both derision and ridicule. He means it. "Eat me.”

Keith smiles - a merciless smile that speaks more of Lance’s impending doom than contentment or satisfaction - and kisses Lance again, even harder than before. _Gladly_ is what Lance hears in the drag of teeth along his neck. The sensation of it all stirs heat in Lance’s stomach, pooling down to his balls. He has no doubt Keith will do exactly as he asks. Keith will devour him.

The subtle mental push is ever-present, disproving any lingering fear that Keith isn’t into him. A strange emotion washes over Lance, like a river’s current and he’s drowning. Keith is all or nothing, never half in and never half out. His touches are as fearless as his kisses and Lance is listening to him now, for maybe the first time.

Each place their bodies touch is lit on fire. Lance loves easily. It falls from him like a waterfall while Keith keeps his sealed tight in a glass bottle. Yet, Lance feels it traced over the contours of hips and the slope of his neck, strung from the tips Keith’s fingers.

_Keith needs him. Keith needs him. Keith needs him._

His mind is stuck on that mantra as Keith trails down his chest and dips his tongue into his navel, down further and he yanks down Lance’s jeans. Still rough, still impatient. He strips Lance down to only his boxers, looking more pleased with himself as he sits back to admire his work.

Lance spreads his legs, trusting, and sucks in a breath as Keith closes his mouth over his clothed erection. Keith is focused, intent on Lance’s pleasure, and Lance can’t think of anything but how lucky he is to be on the end of that because when Keith is all in, he’s at a thousand percent.

By the time Keith pulls him free from his underwear, Lance is babbling incoherent nonsense. He spills how much he wants Keith, thinks of Keith, _loves_ Keith, and it all comes out unbidden and raw and true. Drool pools at the corner of Keith’s mouth and Lance can’t help but find it endearing. He gives sloppy blow jobs, _good_.

It doesn’t matter. They have no secrets.

Unable to restrain himself a second longer, Lance grabs a fistfull of his hair, pulls, and Keith outright moans. The sound is low and melodic as it blends with the slick and wet sounds of his mouth moving up and down. That song rings in Lance’s ears, leaving him torn between pulling Keith up to him, wanting so badly to him again, and simply give in to the divine heat that Keith is wrapped around him.

When he catches Keith shoving his own hand down the waistband of his boxers, Lance decides to act. “C’mere,” he whines, yanking hard enough on Keith’s hair to get his point across. “Wanna touch you.”

With a frustrated huff at being interrupted, Keith complies, sliding up and letting Lance reposition him so he’s on his stomach and Lance is rutting against him. It’s not graceful but it feels good and a rush of excitement surges through Lance when he reaches into Keith’s underwear.

His fingers curl around Keith’s length and he’s somehow surprised at how soft his skin is. He gives a tentative stroke and Keith hisses, hips rolling backward and into Lance’s groin. They’re not going to last much longer.

“I wouldn’t mind if you were inside me,” Keith blurts out. “ _Really_ inside me. Just - _fuck_ \- being filled with you. I wouldn’t mind.”

A string of curses fall from Lance’s mouth and he quickens the speed of his hand to match the thrusts he pushes against Keith’s backside. He is painfully hard, grinding hard against the fabric of Keith’s boxers. Part of him wants more, _needs_ more than this he doesn’t want to stop what he’s doing.

Keith is loud, unraveled, and Lance is left in quiet awe. He dips his thumb into the tip of Keith’s dick and bites down on his neck as releases into the damp fabric of his underwear.

Keith isn’t far behind, gasping when he comes and Lance strains to see his face, beautiful pink lips falling open in a breathless moan.

They fall down in an awkward tangle on the bed and Lance pulls Keith’s back against his chest while they both struggle to catch their breath.

“We never even got naked,” Lance says, disappointed somehow.

Keith gives a light laugh beside him. “Gotta save some stuff for later.”

And Lance recognizes what wraps around him then, even if just for a minute. Contentment, pure and real, and utterly _Keith_.

**Author's Note:**

> Comments and/or kudos are always appreciated! If you're at all interested in the expansion of this story, please let me know.


End file.
